Provide a clear expense policy
Do your colleagues, teams and/or departments know exactly how much they are allowed to spend, on what, in what situations and whom they need to ask for approval (if the case)?
Few people will immediately be crazy about the idea of a watertight spending policy, but it is very important to set boundaries and avoid grey areas.
Make sure that (all) budgets are easy to handle, and are based on the spending habits and liquidity of the company.
So, a document which employees can claim which types of expenses. And, what the budget limits are per day, week or month. For example a maximum of 50 euros per employee per month for business meals.
You can set rules on which payment methods may be used, what types of receipts or invoices you accept and what transactions details are needed for a justification.
This transparency helps everyone in your company make better decisions and be more conscious of business expenditure.